Parkinson's disease (PD) is a neurodegenerative disorder affecting approximately one million Americans. All patients develop a gradually progressive combination of signs and symptoms, including tremor, rigidity, slowness of movement, drooling, low volume speech, micrographia, gait and balance difficulty, and difficulty with activities of daily living. It is known that patients with PD have a loss of dopamine containing neurons projecting from the substantia nigra to the striatum, and most clinical signs and symptoms respond to replacement therapy with doparminergic medications (ie. levodopa, dopamine agonists). However, the underlying mechanism of neurodegeneration is unknown and therefore, to date, there is no treatment to cure or slow the progression of the disease. Many treatments have been hypothesized to be neuroprotective based on in vitro studies and animal data, but clinical trials have not found these drugs to be neuroprotective in patients with PD. The lack of a neuroprotective treatment has been a serious problem for patients, caregivers, health professionals, and for the economy. As the disease progresses the cost of care increases, with estimates of annual cost for medical care going from $3,000/yr early in the disease course to $15,000/yr in later stage disease. Finding a medication(s) that will slow or halt the progression of PD is therefore a major goal of PD research. To this end creating a multi-center study group to run clinical trials of potential neuroprotective agents has been set as a goal of the NIH. This application has, as its specific aim, to be one of the NIH Clinical Centers for neuroprotection treatment trials. This application proposes to create a consortium of centers at the Mayo Clinic and Sun Health Research Institute in order to best be able to enroll patients with early PD for neuroprotection treatment trials. With the mandate to enroll two patients/month for 42 months, the proposed consortium expects to meet these recruitment goals. Mayo Clinic Scottsdale, Mayo Clinic Jacksonville, Mayo Clinic Rochester, and Sun Health Research Institute, all have clinical centers that specialize in the care and treatment of patients with PD, and all have well established clinical trials experience. The resources are available to run clinical trials with a dedicated physician staff of 10 neurologists specializing in treatment of Parkinson's Disease at these four sites, along with nursing staff and the physical plant required. The protocols will be developed by the PIs of the various clinical centers along with NIH staff.